Propanepolyphosphonate compounds



United States Patent 3,400,176 PROPANEPOLYPHOSPHONATE COMPOUNDS Oscar T. Quimby, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio N0 Drawing. Filed Nov. 15, 1965, Ser. No. 507,662 9 Claims. (Cl. 260-932) This invention relates to a new class of propanepolyphosphonate compounds, a process for preparing such compounds and to detergent compositions containing them. More particularly, the present invention has as its primary object providing propanepolyphosphonic acids as well as water-soluble salts and esters thereof, processes for preparing same and detergent compositions containing such compounds.

According to the present invention, there is provided a new class of propanepolyphosphonate compounds corresponding to the following formula:

ZZZ

GENE RAL F0 RMULA in which Z can be hydrogen or a PO G group in which G represents hydrogen, a cation giving a water-soluble salt, or a lower alkyl group containing from 1 to about 6 carbon atoms, and in which at least four Zs are PO G The term propanepolyphosphonate, as used in the description of the present invention, is intended to refer only to polyphosphonate compounds containing at least four phosphonate moieties per compound and expressly excludes mono-, di-, and tri-phosphonates.

As noted, the general formula, shown above, includes several isomeric forms and it is intended that each one falls within the broadest scope of the present invention. The general isomeric forms include the following:

POsGz H H FORMULA I IiOsGz r H IIO Gz 9- PO3G2 H FORMULA II ITOsGz II O3Gz H POgGz a t-r POaGz H POaGg FORMULA III POaGz POsGz III-( 3 C C-H ROsGz P O- G &

FORMULA IV POaGz HC C C-H l OaGz I OaGz I I FORMULAV In the structural formulas presented above, the acid forms exist when G is hydrogen; for example, propane-1, l,2,3,-tetraphosphonic acid (I); propane-1,2,2,3-tetraphosphonic acid (II); propane-1,1,3,3-tetraphosphonic acid (III); propane-1,1,2,2-tetraphisphonic acid (IV); propane-1,1,2,2,3-pentaphosphonic acid (V); Propane-1, 1,2,3,3-pentaphosphonic acid (VI); and propane-1,'1,2,2,3, 3-hexaphosphonic acid (VII).

The cation giving a water-soluble salt can be an alkali metal, e.g., sodium, potassium, lithium, etc., ammonium, substituted ammonium such as monoand diethanol am monium, and the like. Illustrative and representative compounds are: monosodium propane-1,1,3,3-tetraphosphonate; disodium propane-1,1,3,3-tetraphosphonate; trisodium propane-1,1,3,3-tetraphosphonate; tetrasodium propane-1,1,3,3-tetraphosphonate; pentasodium propane- 1,1,3,3,-tetraphosphonate; hexasodium propane-1,1,3,3- tetraphosphonate; heptasodium propane-1,1,3,3-tetraphosphonate; octasodium propane-1,1,3,3-tetraphosphonate; and the corresponding potassium and lithium salts. Ammonium and substituted ammonium compounds can also be prepared such as mono-, di-, and triethanolammonium propane-1,1,3,3-tetraphosphonates. Similar water-soluble compounds can be prepared of each of the propane polyphosphonic acids depicted in Formulae I-VII.

In each of the formulae given above, the lower alkyl group can be a straight chain or branched chain saturated aliphatic radical. Examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl and isohexyl. Illustrative and representative examples are tri(isopropyl) propane-l,1,3,3-tetraphosphonate, tetra(isopropyl)propane l,l,2,3 tetraphosphonate, penta ('butyl) propane-1,2,2,3-tetraphosphonate. The corresponding mono-, di-, tri-, tetra-, penta-, hexa-, heptyl and octyl substituted compounds of the balance of the foregoing alkyl groups can also be made.

Although tetra-, penta-, and hexaphosphonic compounds are described herein, the tetraphosphonic compounds represent the preferred embodiment of the present invention. The most preferred form of the tetraphosphonates are propane-1,1,2,3-tetraphosphonates (Formula I above); and propane-1,2,2,3-tetraphosphonates (Formula II above); and propane-l,1,3,3-tetraphosphonates (Formula III above).

POaGg POaGz Preparation of propane tetraphosphonate compounds The propane-1,1,3,3-tetraphosphonate compounds of the present invention are prepared by reacting an alkalimetal carbanion of a tetra lower alkyl methylenediphosphonate with at least a stoichiometric amount of a dihalomethane in the presence of an organic solvent having no active hydrogen atoms at a temperature in the range of from about 30 C. to about 125 C. for a time period of from about 10 hours to about hours. It is preferred to operate in a temperature range of from 40 C. to C. for from 25 to 75 hours.

It has been surprisingly discovered that the reaction between the alkali metal carbanion of methylenediphosphonate and the dihalomethane proceeds directly to the preparation of propane-1,1,3,3-tetraphosphonate compounds. This could not have been predicted. It could not be expected, for instance, that about 4.5 moles of dichloromethane would react with one mole of methylenediphosphonate carbanion to form exclusively a propane-l,1,3,3- tetraphosphonate compound. The expected straightforward chlorine displacement would produce predominantly 3 ethane-Z-chloro-l,l-diphosphonate; for displacement of the second chlorine of the dichloromethane by a carbanion should be diflicult in the presence of such a large excess of the dichloromethane. The expected result, however, does not occur. What actually appears to happen is that the attachment of the first methylenediphosphonate moiety activates the second chlorine so that it is more readily displaced by a second carbanion moiety than are either of the chlorine atoms of unreacted dichloromethane. This results in the direct preparation of a propanel,1,3,3-tetraphosphonic ester even in the presence of a large excess of the dihalo compound. In fact, a preferred embodiment of the present invention calls for the use of an excess of the dihalomethane compound although the reaction proceeds even at stoichiometric amounts of the reactants. According to the preferred embodiment, the methylenediphosphonate carbanion and the dihalomethane are mixed in a molar ratio of said carbanion to said dihalomethane of from about 1:0.55 to 1:10 and preferably from 1:0.75 to 1:5.

The alkali metal carbanion of tetraalkyl methylenediphosphonate has a formula of MCH(PO R in which M represents an alkali metal such as sodium, potassium or lithium. The preferred alkali metals are sodium and potassium. The R in the formula represents a lower alkyl radical containing from about 1 to about 6 carbon atoms. The ethyl, propyl, isopropyl butyl and isobutyl alkyl groups are preferred. The methyl ester is considerably less soluble in the organic solvent which has been found essential for the present invention. For this reason, the methyl ester is less preferred than the others but it can nevertheless be used. The esters wherein the alkyls have five and six carbons are also less preferred because they react slower than the esters with 2-4 carbon atoms.

Examples of methylenediphosphonate carbanions which can be used in practicing the present invention are sodium salts of tetraethyl methylenediphosphonate carbanion, tetraisopropyl methylenediphosphonate carbanion, and tetrabutyl methylenediphosphonate carbanion. The corresponding potassium and lithium salts can also be used as well as the other esters in which the lower alkyls have up to about 6 carbon atoms.

In the dihalomethane reactant, CH X the halogen X is preferably chlorine or bromine. The chloride is strongly the more preferred salt but the bromide can also be used. It is possible also to use a chlorobromide compound. Other halogens, on the other hand, such as fluorine and iodine require such extraordinary conditions and precautions that they are less preferred. Fluorine, for example, due to its lower reactive rate would require an autoclave and iodine presents a severe color problem in the reaction mixture.

The preferred dihalomethanes are fairly low boiling liquids. Their boiling points to a considerable degree determine the reaction temperature. Dichloromethane has a boiling point of about 40 C., chlorobromomethane, about 69 C.; and dibromomethane, about 98 C.

An unbalanced equation for the reaction between the tetraalkyl methylenediphosphonate carbanion and the dihalomethane to prepare a propane-1,1,3,3-tetraphosphonate ester and an alkali metal halide salt is presented below.

The tetraphosphonate ester is thereafter hydrolyzed as described hereinafter to yield the acid. Neutralization of the acid results in formation of desired salts.

Preparation of methylenediphosphonate carbanion The manner by which the methylenediphosphonate carbanion reactant is prepared forms no part of the present invention. The following general description illustrates suitable methods.

The synthesis of the carbanion essentially involves,

4 as a first step, an oxidation reduction type of a reaction between a metallating agent such as sodium, potassium, lithium, the hydrides of these alkali metals, or a potassiumsodium alloy, and a tetraalkyl ester of methylenediphosphonic acid. The reaction is highly exothermic and it is essential that it be conducted at low temperatures, e.g., on the order of 0 C. to 35 C., preferably between 15 C. and 30 C. The reaction product is a carbanion derived by displacement of hydrogen from the active methylene grouping present in the parent methylenediphosphonate ester starting material using sodium as the metallating agent and with R being as defined above, the equation for this reaction is as follows:

This, in turn, is the carbanion reaction product which, as mentioned above, is then reacted with the dihalomethane in order to prepare the desired propane-1,1,33- diphosphonate.

A specific tetraalkyl ester of methylenediphosphonic acid useful as a starting material for preparing the methylenediphosphonate carbanion can be prepared according to the following method.

Tetraisopropyl methylenediphosphonate 624.7 gm. of triisopropyl phosphite (3 moles, 681 ml.) and 173.9 gm. of dibromomethane (1 mole, ml.) were combined in a reaction apparatus composed of a 1-liter, 3-neck flask fitted with a magnetic stirrer, a thermometer, and a fractionating column for separating the isopropyl bromide by-product from the refluxing mixture. The fractionating column was constructed from a 36-inch Liebig condenser that had been modified to accommodate A-inch glass helices as packing. A Barrett distilling receiver, which had been modified .by the addition of a thermometer well and thermometer was connected to the top of the fractionating column; and to the top of the Barrett receiver was fitted a Dewar condenser cooled with Dry Ice and protected from atmospheric moisture by a drying tube. The temperature of the reaction mixture was quickly brought to reflux at 143 C. The temperature of the circulating water in the packed reflux condenser was maintained 'at 65 C. This temperature was suflicient to return unreacted starting material and allow the by-product isopropyl bromide to be distilled. The heat in-put to the reaction was such that vigorous refluxing continued as the temperature of the mixture slowly increased. After about two hours of heating the first distillate was observed, and after five hours a total of 33 gm. of isopropyl bromide had been collected. The temperature of the reaction mixture was allowed to increase to 185 C. over a twelve-hour period, and by means of an electronic temperature controller it was held there for the remainder of the reaction.

After approximately 16 hours, the reaction was essentially complete as judged by the yield of isopropyl bromide, 231 gm., which represented a yield of about 92%. Further heating served no useful purpose, although reaction times of 20 hours were employed on occasion.

When the reaction was complete, the reaction mixture was transferred to a distilling flask and the low boiling materials (excess phosphite, etc.) were removed through a short one-piece still under a vacuum of 0.1 mm. of mercury and head temperatures up to 50 C. At this point, the contents of the flask weighed approximately 330 gm. and were 93% to 95% tetraisopropyl methylenediphosphonate. The purity of this material was sufficient to proceed in the synthesis of the novel compounds of this invention.

If a purer product is-desired, a high capacity vacuum pump can be introduced into the system and the pressure reduced to 0.005 mm. of mercury. The material boiling between C. and 116 C. is collected and redistilled through an electrically heated 24-inch Vigreaux column.

A complete example of this type of process is presented in a copending patent application, Ser. No. 218,862, filed Aug. 23, 1962, by Clarence H. Roy.

In the preparation of the tetraalkyl ester reactant, particular care must be taken to insure that the starting materials are pure and freshly distilled because the presence of acidic residues in the product causes premature decomposition upon attempted distillation. If this occurs, the product must be neutralized at once, whereupon distillation may be resumed. The neutralization is time consuming and laborious, and is not recommended as an alternative to initial purification of reactants.

It should be noted that a product obtained by fractionation through a Vigreaux column is very nearly as pure as that obtained by careful fractionation through a 24-inch spinning band column; also the yield is much improved because the faster throughput reduces heating time and, consequently, reduces the amount of undistillable resinous residues. The resinous residue in the flask should not be discarded, however, because hydrolysis of this material will yield methylenediphosphonic acid of remarkable purity.

The tetraalkyl methylenediphosphonate compound prepared according to the process just described or the process described in the copending application noted above can be used in this invention as illustrated in the example below.

The reaction between the carbanion reactant and the dihalomethane requires the use of an organic solvent having no active hydrogen atoms in the molecule. If a solvent such as water or alcohol is used which contains a hydrogen atom which is fairly easily removed and which, in an ordinary chemical sense, represents a reactive hydrogen, the desired reaction becomes impossible. The principal purpose for having a solvent is to keep the tetraalkyl methylenediphosphonate carbanion compound in solution. The carbanions disclosed above yield highly viscous or gelatinous solutions, and may even precipitate out as a solid if insufiicient solvent is used. The amount of solvent which is used for the reaction is dependent upon the solubility characteristics of the particular carbanion being used.

The organic solvents which can be used include hexane, toluene, benzene, ethyl ether, tetrahydrofuran, dimethoxyethyl ether, and the like. Of the aforementioned organic solvents, although all work fairly well, the preferred ones are toluene and benzene. The amount of sol vent employed can be readily determind to suit the particular solubility characteristics of the specific ester which is being used. Generally, on a volume basis it has been found that from about 100 ml. to a liter of solvent can be used for each mole of the tetraalky methylenediphosphonate carbanion which is used. Within this general range it is preferred to operate with from about 200 ml. to about 800 ml. per mole of said carbanion.

As mentioned previously, the temperature of the reaction system is governed considerably by the boiling point of the specific dihalomethane used as a reactant. The reaction mixture comprising the tetraalkyl methylenediphosphonate carbanion alkali metal salt, dihalomethane and the organic solvent are mixed in any order and heated to reflux for the required amount of time. It is also possible to carry out the reaction under pressure, if desired.

Due to the high initial viscosity of the carbanion starting material, it is desirable to provide for continuous mixing of the reaction mixture. While the reaction will proceed without mixing or stirring the reaction mixture, it is desirable to do so and does represent a preferred embodiment of the present invention. Any mixing means is suitable such as ordinary mechanical stirring.

A technique has been devised which allows for readily determining when the reaction has gone to completion. It consists of determining the relative peak areas in the phosphorus magnetic resonance (P MR) spectrum of the mixture. The chemical shifts, relative to the P in H PO (sealed in a capillary) taken as zero, are as follows for the species encountered:

Chem. shift in p.p.m.

Any solvent still present at the completion of the reaction is removed by distilling it off. This can be done by following an ordinary distillation technique.

Sodium chloride, which is a by-product of the reaction, can readily be separated from the reaction product by an ordinary washing treatment such as with a chloroformwater mixture. The sodium chloride will be dissolved in the water and the propane-1,1,3,3-tetraphosphonate ester formed by the reaction will be dissolved in the chloroform layer. The sodium chloride-water solution can be decanted, and if desired, the sodium chloride can be recovered therefrom.

The tetraalkyl ester of the propane-1,1,3,3-tetraphos phonic acid can be obtained at yields in excess of 80%. It can be purified by simple distillative means after removal of by-product salts. This can be done by vacuum distillation to strip out most of the volatile impurities. The ester product can be converted directly to the free phosphonic acid by methods known to those skilled in the art, namely by hydrolyzing with boiling concentrated hydrochloric acid in a temperature range of from about C. to C. for about 4 hours. Alternatively, in the case of isopropyl esters, an excellent novel pyrolytic process is described in a copending patent application, Ser. No. 218,863, filed Aug. 23, 1962, by Clarence H. Roy. Neutralization of the acid by addition of a suitable base such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, diethanolammonium hydroxide results in the formation of the corresponding salts which are within the scope of the present invention.

The fOllOWing example illustrates the foregoing description and a preferred mode of operation according to the present invention.

EXAMPLE Part APreparation of the sodium carbanion of tetraisopropyl methylenediphosphonate Reaction apparatus consisted of a one-liter three-necked flask, fitted with a thermometer, a high speed stirrer, and a 50 ml. offset additive type separatory funnel leading to an Allihn condenser. All equipment was baked at for 30 minutes prior to assembly, purged with nitrogen, and a drying tube filled 50:50 with Drierite and Ascarite was attached to the condenser to minimize entrance of CO or H O into the reaction vessel.

Two moles of sodium (45.98 grams) and ml. of toluene were placed in the reaction flask, heated to 110 C. and stirred at 9,000-10,000 rpm. for five minutes in order to prepare a fine dispersion. Heating was stopped and stirring Speed maintained until the temperature dropped to 85 C., then was slowed to give steady agitation during further cooling and throughout the reaction. After the dispersions temperature was cooled to 25, two moles (688.7 grams) of tetraisopropyl methylenediphosphonate were added dropwise over a 1 hour, 15 min. period to the mixture, producing an immediate evolution of heat and hydrogen. The reaction temperature was kept between 25 C. and 35 C. by cooling with a Dry Ice bath. The sodium was consumed within 20 minutes after all the diphosphonate was added. The reaction product was virtually 100% of sodium carbanion of tetraisopropyl methylenediphosphonate, as shown by P MR spectrum.

Part BReaction of the carbanion from Part A and dichloromethane The reaction apparatus consisted of a three-neck twoliter flask fitted with a magnetic stirrer, a thermometer, and a Y adapter leading to another thermometer (to measure vapor temperature) and to a Graham condenser. It may be noted that tap water cooling in the Graham condenser was sufiicient to collect all dichloromethane, CH Clproven by connecting a Dry Ice trap to the Graham condenser during the first eight hours of reaction. A vent to the atmosphere was provided through a drying tube filled with Drierite and Ascarite.

4.3 moles (365 grams) of dichloromethane were added to the tetraisopropyl methylenediphosphonate carbanion prepared in Part A above, combined in the reaction flask and refluxed for 50 hours, the pot temperature slowly rising from 61 to 72 at the end of 32 hours, as the carbanion was consumed.

After the reaction was completed, the solvent and excess dichloromethane were removed by vacuum distillation, and the residual material was dissolved in one liter of water. This solution was extracted with seven 250 ml. chloroform, HCCl washes, the HCCI solution being back-washed with two 100 ml. H O washes to remove ionic materials. (The second water wash gave a negative test for halide ion with HNO -l-AgNO The concentrated chloroform solution gave 642 grams of ester which contained (as shown by P MR spectra) 84% propane l,1,3,3-tetraphosphonate. The impurity was predominantly tetraisopropyl methylenediphosphonate, CH [PO(OC H which was removed by vacuum distillation, collecting everything distillable from 105 at 140 microns pressure to 111 at 300 microns pressure.

Part C-Conversion to acid and salt The remaining undistillable material comprising the octaisopropyl propane-1,1,3,3-diphosphonate was converted to the propane-1,1,3,3-tetraphosphonic acid by refluxing for five hours with a 100% molar excess of concentrated aqueous HCl. With larger batches, it is necessary to make provisions to remove the C3HI'1C1 as it is evolved to prevent continual lowering of the solutions boiling point.

The acidic solution was concentrated by vacuum distillation, then azeotroped three times to remove traces of HCl and H 0. The acid was decolorized by dissolving in 750 ml. of H and stirring with copious amounts of charcoal for one hour before filtering. The solution was diluted to two liter volume, and the acid converted to the aniline salt by adding aniline (in excess) to the solution, then removing the excess by ether extraction.

The salt was purified by recrystallizing twice from 4:1:4 methanol/H O/acetone, obtaining a product melting at 179 C. This was in turn converted to the Na H salt by titrating to pH 9.2 with NaOH, and the aniline removed by ether extraction. The salt was recovered by simply concentrating the solution to dryness.

Analysis.Na H Calculated for C H O P Na C, 7.27; H, 1.22; P, 24.98; Na, 27.81. Found: C, 7.5; H, 1.79; P, 24.4; Na, 24.3.

A portion of the sodium salt, Na l-l was converted to the acid by an ion exchange reaction. The analysis for the dry acid was:

Analysis.-Acid: Calculated for C H O P C, 9.90; H, 3.32; P, 34.04. Found: C, 10.2; H, 3.4; P, 34.5.

In the preceding example, corresponding lower alkyl esters can be prepared by starting with a different ester derivative in place of the isopropyl ester. Likewise, the dichloromethane can be replaced by dibromomethane. In place of the sodium carbanion salt, potassium or lithium salts can be substituted; and the toluene solvent can be replaced by hexane or benzene. Final neutralization can be carried out to any desired sodium salt, or alternatively, any other previously disclosed water-soluble salt.

The sodium salts of PTeP 1133 from Na H through Na H have relatively high water solubilities, as the following tabulation shows:

Degree of So1n., Wt. pH of Neutralization Percent H10 Soln NmHr Salt 67. 7 4-5 NasHa Salt 64. 5 NaaHz Salt 61. 8 10. 5-11 N37H2 Salt 60. 6 Nag Salt Ca. 13

Salts containing three sodiums or less are relatively acid, giving solutions of pH 3.5 or lower.

The preparation of the propane-1,1,2,3-tetraphosphonate compounds and the propane-1,2,2,3-tetraphosphonate compounds employs a reaction system similar to that described above for the 1,1,3,3 isomeric tetraphosphonate. The reaction conditions are generally the same except that somewhat higher temperatures can be used in preparing the 1,1,2,3 and 1,2,2,3 isomers and, thus, the reaction proceeds more rapidly.

Basically, the reaction for preparing propane-1,1,2,3- tetraphosphonate and propane-1,2,2,3 tetraphosphonate compounds involves a reaction between monobromomethanephosphonate (R O PCH Br, in which R has the same meaning as previously) and an alkali metal carbanion of tetraloweralkylmethylenediphosphonate in a solvent such as toluene and heating to about 110-120 C. The carbanion has been discussed in detail above.

The equations for the reactions involved are as follows, wherein the R and M symbols have the same meaning as ascribed in the foregoing discussion The reaction product from Equation 2, immediately above, then reacts with monobromomethylenephosphonate to form either the propane-l,l,2,3-tetraphosphonate ester as follows: 1

or the propane-1,2,2,3-tetraphosphonate ester as follows:

R203PCH2CM 2 R O PCH Br z s z 2 s a 2 l' Synthesis of the pentaphosphonate and hexaphosphonate compounds employing related chemistry will be apparent from the foregoing discussion.

Another of the surprising discoveries of the present invention is the remarkable detergency building property of the novel propanepolyphosphonate compounds of the present invention. The magnitude of the cleaning power relative to previously known standard organic and inorganic deterg'ency builder compounds was totally unexpected. As a result of this discovery, one of the more important embodiments of the present invention is a detergent composition which contains a propanepolyphosphonate compound described herein as a builder component in the complete detergent formulation.

Built detergent compositions ranging from lightly built to medium built to heavily built have been available for several years. These compositions most generally are in the form of solids and liquids and are used for light, medium, or heavy duty cleaning purposes. The meaning of the terms lightly built, medium built, and heavily built is derived from the relative amount of builder which is present in the total formulation; for instance, a product designed for laundering soiled fabrics. The concept behind built detergent compositions is based on the knowledge that when certain substances are added to the active component or components of detergent compositions, an increase in cleaning ability or whiteness maintenance, or both, is obtained, even though the washing solution used may contain less of the active detergent. Substances capable of producing this improved effect are known as builders, and it is in this context that the propanepolyphosphonate compounds of the present invention are especially valuable. Light duty detergent compositions are used for washing fine fabrics or lightly soiled fabrics. Milder conditions are generally used in light duty applications, such as, for instance, cool or warm water and only slight wringing or agitating. Dishwashing compositions can also be considered as light duty detergent compositions. Heavy duty laundering compositions, on the other hand, are those intended for washing heavily soiled fabrics such as are generally found in an ordinary household wash. Medium duty laundering compositons can alternatively be used for dishwashing, fine fabric launder+ ing, or for washing fairly heavily soiled fabrics.

It is surprising that the compounds of the present invention find such broad application in the field of built detergent compositions. It was equally surprising to discover that in formulating detergent compositions described above, the active detergent portion of the complete compositions could be virtually any of the known or commercially available surface active detergent compounds. In its broadest terms, therefore, this embodiment of the present invention contemplates a detergent composition comprising an active detergent portion which can be any surface active compound having useful detergent properties and an effective amount of a builder comprised of the propanepolyphosphonate compounds described herein.

It is to be noted that while active detergents or mixtures of detergents are essential components in the built detergent compositions presently being contemplated, the major discovery resides in the useful builder properties of the propanepolyphosphonates and, as mentioned earlier, especially the propanetetraphosphonates.

According to the present invention, a detergent composition contains an active detergent and a propanepolyphosphonate builder in a ratio, by weight, of from about :1 to about 1:10 and, preferably, in a weight ratio of detergent to builder of from 2:1 to about 1:6. It is customary to speak of the ingredients in detergent compositions as being by weight. By way of example, a detergent composition prepared according to the present invention in which the active to builder ratio is about 5:1 or 1:1 on a weight basis is especially useful as a dishwashing composition or a fine fabric laundering composition. A detergent composition having a detergent to builder ratio of 1:15 or 1:2 has excellent performance characteristics for Washing lightly soiled items in an ordinary household r wash. Yet further by way of illustration, heavily soiled fabrics are best laundered with detergent compositions in which the active detergent to builder ratio is from about 1:2 to about 1:10.

It will be seen, therefore, that in practicing the present invention in its simplest terms, it is only necessary to mix at least one surface active detergent compound having the desired sudsing, cleaning, mildness characteristics and the like, with an effective amount of a propanepolyphosphonate builder compound in the useful by-weight proportions set forth above.

The active detergent ingredients can include anionic, nonionic, ampholytic and zwitterionic detergent compounds, or mixtures of compounds selected from these general classes of detergents. Each of these classes is illustrated at length as follows:

A. Anionic soap and non-soap synthetic detergents This class of detergents includes ordinary alkali metal soaps such as the sodium, potassium, ammonium and alkylolammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms and preferably from about 10 to about 20 carbon atoms. Suitable fatty acids can be obtained from natural sources such as, for instance, from plant or animal esters (e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, whale and fish oils, grease, lard, and mixtures thereof). The fatty acids also can be synthetically prepared (e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process). Resin acids are suitable such as rosin and those resin acids in tall oil. Napthenic acids are also suitable. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap.

This class of detergents also includes water-soluble salts, particularly the alkali metal salts of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester radical. (Included in the term alkyl is the alkyl portion of higher acyl radicals.) Examples of this group of synthetic detergents which form a part of the preferred built detergent compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C C carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, especially those of the type described in United States Letters Patent No. 2,220,099 and 2,477,383; sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about 1 to about -10 units of ethylene oxide per molecule and in which the alkyl radicals contain about 8 to about 12 carbon atoms.

Additional examples of anionic non-soap synthetic detergents which come within the terms of the present invention are the reaction product of fatty acids esterified with isothionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of methyl tauride in which the fatty acids, for example, are derived from coconut oil. Other anionic synthetic detergents of this variety are set forth in United States Letters Patents 2,486,921; 2,486,922; and 2,396,278.

Still other anionic synthetic detergents include the class designated as succinamates. This class includes such surface active agents as disodium N-octadecylsulfo succinamate; tetrasodium N-(1,2-dicarboxyethyl)-N-octadecyl-sulfo-succinamate; diamyl ester of sodium sulfosuccinic acid; dihexyl ester of sodium sulfosuccinic acid; dioctyl ester of sodium sulfosuccinic acid.

Anionic phosphate surfactants are also useful in the present invention. These are surface active materials having substantial detergent capability in which the anionic solubilizing group connecting hydrophobic moieties is an oxy acid of phosphorus. The more common solubilizing groups, of course, are -SO H, -SO H, and CO H. Alkyl phosphate esters such as (RO) PO H and ROPO H in which R represents an alkyl chain containing from about 8 to about 20 carbon atoms are useful.

These esters can be modified by including in the molecule from one to about 40 alkylene oxide units, e.g.,

11 ethylene oxide units. Formulae for these modified phosphate anionic detergents are in which R represents an alkyl group containing from about 8 to carbon atoms, or an alkylphenyl group in which the alkyl group contains from about 8 to 20 carbon atoms, and M represents a soluble cation such as hydrogen, sodium, potassium, ammonium or substituted ammonium, and in which n is an integer from 1 to about 40.

A specific anionic detergent which has also been found excellent for use in the present invention is described more 24 carbon atoms, said mixture of positional isomers ineluding by weight about 10% to about of an alphabeta unsaturated isomer, about to about 70% of a beta-gamma unsaturated isomer, about 5% to about 25% of a gamma-delta unsaturated isomer, and about 5% to about 10% of a delta-epsilon unsaturated isomer;

(b) Said Component B is a mixture of water-soluble salts of bifunctionally-substituted sulfur-containing saturated aliphatic compounds containing from about 10 to about 24 carbon atoms, the functional units being hydroxy and sulfonate radicals with the sulfonate radical always a being on the terminal carbon and the hydroxy radical being attached to a carbon atom at least two carbon atoms removed from the terminal carbon atoms; and

(c) Said Component C is a mixture of water-soluble salts of highly polar saturated aliphatic compounds, each having two sulfur-containing moieties, one of which must be a sulfonate group attached to the terminal carbon atom and the other moiety selected from the group consisting of sulfonate and sulfate radicals attached to a carbon atom at least two carbon atoms removed from the terminal carbon atom, said compounds containing from about 10 to about 24 carbon atoms.

B. Nonionic synthetic detergents Nonionic synthetic detergents may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility, has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where polyoxyethylene content 12 is about 50% of the total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

(1) The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 5 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octene, or nonene, for example.

(2) Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. For example, compounds containing from about 40% to about polyoxyethylene by weight and having a molecular Weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobicbase constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000, are satisfactory.

(3) The condensation product of aliphatic alcohols having from 8 to 22 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 5 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.

(4) Nonionic detergents include nonyl phenol condensed with either about 10 or about 30 moles of ethylene oxide per mole of phenol and the condensation products of coconut alcohol with an average of either about 5.5 or about 15 moles of ethylene oxide per mole of alcohol and the condensation product of about 15 moles of ethylene oxide with one mole of tridecanol.

Other examples include dodecylphenol condensed with 12 moles of ethylene oxide per mole of phenol; dinonylhenol condensed with 15 moles of' ethylene oxide per mole of phenol; dodecyl mercaptan condensed with 10 moles of ethylene oxide per mole of mercaptan; bis-(N- Z-hydroxyethyl) lauramide; nonyl phenol condensed'with 20 moles of ethylene oxide per mole of nonyl phenol; myristyl alcohol condensed with 10 moles of ethylene oxide per mole of myristyl alcohol; lauramide condensed with 15 moles of ethylene oxide per mole of lauramide; and di-iso-octylphenol condensed with 15 moles of ethylene oxide. v 1

(5) A detergent having. the formula R R .R N O (amine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moietyof R which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 ether linkages, and each R and R are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms;

Specific examples of amine oxide detergentsincIude:

dimethyldodecylamine oxide dimethyltetradecylamine oxide ethylmethyltetradecylamine oxide cetyldimethylamine oxide dimethylstea'rylamine oxide cetylethylpropylamine oxide diethyldodecylamine oxide diethyltetradecylamine oxide dipropyldodecylamine oxide bis-(Z-hydroxyethyl)dodecylamine oxide bis-(2-hydroxyethyl)-3-dodecoxy-l-hydroxypropy1 amine oxide (2-hydroxypropyl)methyltetradecylamine oxide dimethyloleylamine oxide dimethyl-(Z-hydroxydodecyl)amine oxide 13 and the corresponding decyl, hexadecyl and octadecyl homologs of the above compounds.

(6) A detergent having the formula R R R P+O (phosphine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from to about 2 hydroxy groups and from O to about 5 ether linkages, there being at least one moiety of R which is an alkyl group containing from about to about 18 carbon atoms and 0 ether linkages, and each of R and R are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms.

Specific examples of the phosphine oxide detergents include:

dimethyldodecylphosphine oxide dimethyltetradecylphosphine oxide ethylmethyltetradecylphosphine oxide cetyldimethylphosphine oxide dimethylstearylphosphine oxide cetylethylpropylphosphine oxide diet-hyldodecylphosphine oxide diethyltetradecylphosphine oxide dipropyldodecylphosphine oxide bis(hydroxymethyl)dodecylphosphine oxide bis-( Z-hydroxyethyl) dodecylphosphine oxide (Z-hydroxypropyl methyltetradecylphosphine oxide dimethyloleylphosphine oxide, and dimethyl-(2-hydroxydodecyl)phosphine oxide and the corresponding decyl, hexadecyl, and octadecyl homologs of the above compounds.

(7) A detergent having the formula (sulfoxide detergent) wherein R is an alkyl radical containing from about 10 to about 28 carbon atoms, from 0 to about 5 ether linkages and from 0 to about 2 hydroxyl substituents at least one moiety of R being an alkyl radical containing 0 ether linkages and containing from about 10 to about 18 carbon atoms, and wherein R is an alkyl radical containing from 1 to 3 carbon atoms and from one to two hydroxyl groups.

octadecyl methyl sulfoxide dodecyl methyl sulfoxide tetradecyl methyl sulfoxide 3-hyd-roxytridecyl methyl sulfoxide 3-methoxytridecyl methyl sulfoxide 3-hydroxy-4-dodecoxybutyl methyl sulfoxide octadecyl 2-hydroxyethyl sulfoxide d'odecylethyl sulfoxide C. Ampholytic synthetic detergents Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic or aliphatic derivatives of heterocyclic secondary and tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and at least one contains an anionic water-solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are sodium 3- (dodecylamino)-propionate i t C12 2sN-CHzCHzC ONa sodium 3-(dodecylamino)propane-l-sulfonate t C 2H25NCHzCH2CH2SO3Na sodium 2-(dodecylamino)ethyl sulfate i C12H2aNCH2CHzOSOaNa sodium Z-(dimethylamino)octadecanoate 0 CIBHZKCHCHD ONa H: C --NC Ha disodium 3- (N-carboxymethyl-dodecylamino propane- 1- sulfonate CHzCHgCHzSOaNa C 12H25N 0 o Hiii ONa disodium 2- (oleylamino) ethyl phosphate H o C Hs5I ICHzCHzO1 (ON8)2 disodium 3 (N -methyl-hexadecylamino) propyl-l -phosphonate CH3 0 owHm lcHtomoHzi (ONa)a disodium octadecyl-iminodiacetate o CXBHK7N(CH2(% ONa)g sodium 1-carboxymethyI-Z-undecyl-imidazole C taHza-N disodium 2 [N-(Z-hydroxyethyl)octadecylamino] ethyl phosphate CHzCH2OIi (ONH)I CisHuN CHaOHzOH and sodium N,N bis (2-hydroxyethyl)-2-sulfato-3-dodecoxypropylarnine OSOaNa C12H25OCHQCIJHCH2N(CH2CH2OH)Q D. Zwitterionic synethetic detergents Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium and phosphonium or tertiary sulfoniu-m compounds, in which the cationic atom may be part of a heterocyclic ring, and in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic su'bstituents contains from about 8 to 18 carbon atoms, and at least one aliphatic su'bstituent contains an ainonic water-solubilizing group, e.g., carboxy, sulfo, sulfato, phosph-ato, or phosphono. Examples of compounds falling within this definition are 3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-l-sulfonate 3-(N,N dimethyl N hexadecylammonio)propane-1- sulfonate I 9 ClflH33N CH2CH2CH2S03 2-(N,N-dimethyl-N-dodecylammonio) acetate 3-(N,N-dimethyl N-dodecylammonio) propionate 2- (N,N dimethyl-N-octadecylammonio) -ethyl sulfate 6 CISHnN-CHzCHzOS 03 C191: 2- (trimethylammonio)ethyl dodecyl-phosphonate ll 33 CuHzsS O CH2C 2 3):

2-(S-methyl-S-tert.-hexadecyl-sulfonio)ethane l sulfonate I R-g-C HzCHzS 03 R =tetralsobutylene 3 (S-methyl-S-dodecylsulfonio) -propinate CH3 0 e CnHzsC HzCHzC-O sodium 2-(N,N-dimethyl-N-dodecylammonio)ethyl phosphonate CH1 0 ONn I ll/ CrzH-zsNCHzCHnP 9 ea 0 CH3 4-(S-methyl-S-tetradecylsulfonio)butyrate I ll 6 Ci4H2tg-CH2CH:CHzCO 1-(Z-hydroxyethyl)-2-undecyl-imidazolium-l-acetate' CnHzr-N O ri l-0 Z-(trimethyl ammonio)-octadecanoate and 3-(N,N-bis-(2-hydroxyethyl)-N-octodecylammonio)- 2-hydroxypropane-l-sulfonate.

/CH:CH2OH C|gNl7g'-CHI IHCH2S03 CHzCHzOH Some of these detergents are described in the following US. Patents: 2,129,264; 2,178,353; 2,774,786; 2,813,898; and 2,828,332.

A detergent composition prepared according to the present invention contains as essential ingredients (a) a detergent ingredient and (b) a builder ingredient. In its simplest terms, a composition can contain a single detergent compound and a single builder compound. 0n the other hand, it frequently is desirable to formulate a detergent composition in which the active detergent portion consists of mixtures of detergent compounds selected from the foregoing classes. Thus, for example, the active ingredient can consist of a mixture of two or more anionic detergents; or a mixture of an anionic detergent and a nonionic detergent; or, by way of another example, the active detergent can be a ternary mixture of two anionic detergents and a zwitterionic detergent.

The part of the complete formulation that functions as a builder can likewise be composed of a mixture of builder compounds. For example, the propanepolyphosphonate compounds described herein, e.g., propane-1,1,3, 3-tetraphosphonate; propane 1,l,2,3-tetraphosphonate; and propane-1,2,2,3-tetraphosphonate, can be used in admixture with each other or in admixture with other watersoluble organic or inorganic builder salts. For example, the propanepolyphosphonates can be mixed with sodium tripolyphosphate or potassium pyrophosphates. Also by way of example, a binary builder mixture can consist of a propanepolyphosphonate compound and a water-soluble organic builders salt such as water-soluble salts of nitrilotriacetic acid, ethylenediaminetetraacetic acid, ethane-1- hydroxy-l,l-diphosphonic acid. Still further, the builder component of a complete formulation can consist of ternary mixtures of these several types of builder compounds on an equal molar or weight basis.

Water-soluble inorganic alkaline builder salts which can be used in this invention in combination with the novel propanepolyphosphonate compounds described herein are alkali metal carbonates, borates, phosphates, condensed polyphosphates, bicarbonates and silicates. Ammonium and substituted ammonium salts of these materials can also be used. Specific examples of suitable salts are sodium tripolyphosphate (mentioned above), sodium carbonate, sodium tetraborate, sodium and potassium pyrophosphate, sodium and ammonium bicarbonate, potassium tripolyphosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium orthophosphate and potassium bicarbonate.

Examples of water-soluble organic alkaline sequestrant builder salts which can be used in admixture with the propanepolyphosphonate compounds of this invention are alkali metal (sodium, potassium, lithium), ammonium or substituted ammonium, aminopolycarboxylates, e.g., the above-mentioned sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyethyl)- ethylenediaminetriacetates, sodium and potassium nitrilotriacetates, sodium, potassium and triethanolammonium N-(Z-hydroxyethyl)-nitrilodiacetates, and the water-soluble salts of ethane-1-hydroxy-1,1,2-triphosphonic acid and ethane-2-hydroXy-l,1,2-triphosphonic acid. The alkali metal salts of phytic acid, e.g., sodium phytate, are also suitable as organic alkaline sequestrant builder salts. Certain other organic builders which can be used in admixture with the propanepolyphosphonates described herein are water-soluble salts of ethylene-l,l-diphosphonic acid, methylene diphosphonic acid, and the like.

The specific action of the builder mixtures of this invention will vary to some extent depending upon the ratio of active detergent to builder mixture in any given detergent composition. There will be considerable variation in the strengths of the washing solutions employed by different housewives, i.e., some housewives may tend to use less or more of the detergent compositions than will others. Moreover, there will be variations in temperature and in soil loads as between washing operations. Further, the degree of hardness of the water used to make up the washing solutions will also bring about apparent differences in the cleaning power and whiteness maintenance results. Finally, different fabrics will respond in somewhat different ways to different detergent compositions. The best type of detergent composition for household use is a composition which accomplishes an excellent cleaning and whiteness maintenance effect under the most diverse cleaning conditions. The built detergent compositions of this invention are especially valuable in this respect.

The builder compounds taught herein are very efiicient. In general, they permit the attainment of excellent washing results with a relatively smaller total quantity of builder in relation to the total quantity of active detergent ingredient than is used in commercially available sodium tripolyphosphate-built detergent compositions.

The built detergent compositions of the present invention can be formulated and prepared into any of the several commercially desirable solid and liquid forms including, for example, granules, flakes, tablets, and waterbased and alcohol-based liquid detergents, and the like. According to one embodiment of the present invention, solid detergent compositions are prepared containing an active detergent (sole active or a mixture of detergents) and a builder (single compound or a mixture) in a by weight ratio (detergent to builder) of about :1 to about 1:10, and preferably from about 2:1 to about 1:6. A special embodiment of this invention is a liquid detergent composition containing an active detergent and a builder in a by weight ratio (detergent to builder) of 3:1 to about 1:10; preferably 2:1 to about 3:1. The potassium salts of the propane-polyphosphonates are especially useful in liquid formulations.

Liquid detergent compositions generally present special problems to the formulator in view of the peculiarities inherent in liquid systems and the special requirements of solubility of the ingredients, and more especially, their physical and chemical stability in such mediums. It is Well known, for instance, that sodium tripolyphosphate, which is used commonly in granular compositions, is generally regarded as being unsatisfactory as a sole builder for liquid detergents. It has a marked propensity to hydrolyze to the lower forms of phosphate compounds which are less desirable builders. As a practical matter, therefore, it has been necessary to use a more stable form of a phosphate builder, i.e., pyrophosphate, notwithstanding the fact that the pyrophosphate is a weaker detergency builder than tripolyphosphate. The propane-1,1,3,3-tetraphosphonate compounds of this invention especially solve this particular formulating problem because they are much better builders than tripolyphosphates and, at the same time, are hydrolytically stable. In view of the increasing acceptance by the general public of liquid detergent compositions for virtually all washing and cleaning situations including laundering and dishwashing, it is a very significant contribution of this invention that an improved built liquid detergent product is made possible that will far outperform known liquid detergents while at the same time being free of the troublesome problem of stability.

Built liquid detergents are usually water based or have a mixture of water and alcohol in the liquid vehicle. Such liquid vehicles can be satisfactorily employed in formulating a composition according to the present invention. Accordingly, a sample built liquid detergent composition of this invention can consist essentially of a detergent ingredient (a single detergent or a mixture of detergents) and a propane-1,1,3,B-tetraphosphonate-containing builder ingredient (either as a single builder or in admixture with other builders), with the balance of the composition being a liquid vehicle such as water or a water alcohol mixture, and the like.

The propanetetraphosphonate compounds of the present invention such as the 1,1,3,3; 1, 2, 2, 3; and the 1,1,2,3 isomers described above, have a valuable property which can be of special advantage in the preparation of built liquid detergent compositions. Upon being added to an aqueous solution, even in very small amounts, the propanetetraphosphonates almost immediately form a cloudy precipitate with the hardness minerals in the solution, especially the calcium therein. This precipitate effectively inactivates or removes the calcium from the solution while at the same time provides a solution thatis cloudy and somewhat milky in appearance. It is well known that there is a substantial proportion of the consumer public that has a decided preference in some applications, e.g., dis'hwashing and hard surface cleaners, for a cloudy, thicker, opaque type of liquid detergent. The builder compounds described herein provide this property and thereby offer an alternative to the use of additional ingredients such as opacifiers and the like.

The detergent compositions of the present invention perform at their maximum level in a washing solution which has a pH in the range of from about 8 to about 11.5. Within this broad range, it is preferred to operate at a pH of from about 9.5 to 11. The detergent and the builder can be neutralized to a degree sufficient to insure that this pH prevails in any washing solution. If desired, other alkaline materials can be added to the complete formulation to provide for any necessary pH adjustments. A preferred embodiment is to have the detergent composition, whether in solid or liquid form, to provide a pH in the aforementioned ranges at the usual recommended usage levels.

In a finished detergent formulation, there can be present other materials which make the product more effective or more aesthetically attractive. The following are mentioned only by way of example. A water-soluble sodium carboxymethyl cellulose can be added in minor amounts to inhibit soil redeposition or for other reasons. Tarnish inhibitors such as benzotriazole or ethylenethiourea can also be added in amounts up to about 3%. Fluorescers, and brighteners, perfumes, coloring agents, while not per se essential in the compositions of this invention, can be added in minor amounts. As already mentioned, an alkaline material or alkaline such as sodium of potassium hydroxide can be added as supplementary pH adjusters. Other usual additives include sodium sulfate, sodium carbonate, Water, and the like. Corrosion inhibitors are also frequently used. Watersoluble silicates are highly effective corrosion inhibitors and can be added if desired at levels of from about 3% to about 8% by weight of the total composition. Alkali metal, preferably potassium and sodium silicates, are preferred having a weight ratio of SiO :M O of from about 1.0:1 to 2.8: 1. (M refers to sodium or potassium.) Sodium silicate having a ratio of SiO :Na O of from about 1.6:1 to 2.45 :1 is especially preferred.

In the embodiment of this invention which provides for a built liquid detergent, a hydrotropic agent may be found desirable. Suitable hydrotropes are water-soluble alkali metal salts of toluenesulfonate, benzenesulfonate, and xylene sulfonate. referred hydrotropes are potassium or sodium toluenesulfonates. The hydrotrope may be added, if desired, at levels of from 0% up to about 12%. While a hydrotrope will not ordinarily be found necessary, it can be added, if so desired, for any reason such as to function as a solubilizing agent and to produce a product which retains its homogeneity at a low temperature.

The following compositions, in which the percentages are by weight, will serve to illustrate, but not limit, the invention. Each of the compositions in the following examples give in solution a pH within the desired range of from about 8 to about 12.

EXAMPLE A An excellent granular built detergent composition according to this invention has the following formulation:

Percent Sodium alkyl benzene sulfonate in which the alkyl is a straight chain dodecyl radical 18 Percent Octasodium propane-1,1,3,3-tetraphosphonate 50 Sodium sulfate' 15 Sodium silicate (ratio of siO zNa O of 2:1) 7 Water 1O This heavily built detergent composition is especially valuable for laundering heavily soiled clothes.

The straight chain dodecyl benzene sodium sulfonate in the preceding composition can be replaced on an equal weight basis by either branched chain dodecyl benzene sodium sulfonate, sodium tallow alkyl sulfate, sodium coconut oil alkyl sulfate, sodium olefin sulfonate as described in the specification derived from alpha olefines having an average of 1018 carbon atoms in the molecule, or a mixture of straight chain dodecyl benzene sodium sulfonate and sodium tallow alkyl sulfate on an equal weight. basis. The octasodium prpane-1,l,3,3- tetraphosphonate builder can be replaced by other sodium salts of this same builder such as the hexasodium dihydrogen salt or the pentasodium trihydrogen salt. It can also be replaced by a 1:1 mixture of sodium tripolyphosphate and hexasodium propane-l,1,3,3-tetraphosphonate; or a 1:1:1 ternary mixture of sodium tripolyphosphate, sodium nitrilotriacetate and hexasodium dihydrogen propane-1 1,3 ,3-tetraphosphonate.

EXAMPLE B Another granular detergent composition having outstanding cleaning properties has the following formulation:

Percent Straight chain dodecyl benzene sodium sulfonate (anionic detergent) 4 Sodium tallow alkyl sulfate (anionic detergent) 4 Dodecyl methyl sulfoxide (nonionic detergent) 2 Hydrogenated marine oil fatty acid 2 Tetrasodium tetrahydrogen propane 1,1,3,3 tetraphosphonate 60 Sodium silicate (ratio of SiO :Na O of 1.611) 10 Sodium sulfate 12 Water 6 In this example, the total active detergent of 10% can be totally the nonionic species. In addition, the 2% dodecyl methyl sulfoxide nonionic detergent can be replaced either by an equal weight basis of an alkylphenol ethylene oxide condensate formed by a condensation reaction between dodecyl phenol and moles of ethylene oxide per mole of dodecyl phenol, or by 3-(dodecyldimethylammonio)-2-hydroxy propane-l-sulfonate.

The tetrasodium salt of the tetraphosphonate builder can be added as the salt or it can be present as the free acid neutralized in situ to correspond to the desired salt form.

In place of the specific tetraphosphonate included in this example, it is possible to use either a hexasodium salt of propane 1,1,2,3 tetraphosphonate or propane- 1,2,2,3-tetraphosphonate or a 1:1 mixture of these latter compounds.

EXAMPLE C This is also an example of a granular detergent composition of outstanding efliciency.

This detergent compound is also referred to as linear dodecyl benzene sodium sulfonate.

In this example, the anionic detergent can be replaced on an equal weight percentage with an olefin sodium sulfonate as described above in which the olefin sulfonate consists of a mixture of chain lengths ranging from 10 to about 1.8 carbon atoms, or a branched chain alkyl benzene sulfonate in which the alkyl is derived from tetrapropylene.

EXAMPLE D The following formulation is for a granular detergent composition that is an outstanding detergent composition:

. Percent Dodecyldimethylamine oxide (nonionic detergent) 16.0 Heptasodium monohydrogen propane-1,1,3,3-tetraphosphonate 40.0

Toluene sulfonate 1.8 Sodium silicate (ratio of SiO ':Na O of 2: l) 8.0 Sodium sulfate 2.0 Diethanolamide of coconut fatty acid 1.9 Benzotriazole .02

Balance to water.

In this composition, the nonionic detergent can be replaced by tetradecyl dimethyl phosphine oxide, sodium-3- dodecylaminopropionate, sodium-3-dodecylaminopropanesulfonate, 3 (N,N-dimethyl N hexadecylammonio)-propane-l-sulfonate or 3 (N,N dimethyl N dodecylammonio) 2 hydroxypropane-l-sulfonate. Twenty percent of the builder can be replaced with an equal weight replacement of trisodium ethane-l-hydroxy-l,l-diphosphonate.

EXAMPLE E .A liquid detergent which is especially effective in cool water as a heavy-duty detergent and has the following composition:

Percent 3(N,N-dimethyl-N-hexadecylammonio) 2 hy- EXAMPLE F Another light-duty-built liquid detergent which is cloudy in appearance consists of:

Percent Sodium salt of sulfuric acid ester of the reaction product of one mole of coconut oil alcohol and 3 moles of ethylene oxide 11..0 Dodecylclimethylamine oxide 6.0 Sodium tallow alkyl sulfate 2.25 Hexapotassium dihydrogen propane-1,1,3,3-tetraphosphonate 12.0 Potassium toluene sulfonate 5.5 Water 63.25

This composition is especially suited for dishwashing and fine fabric washing situations.

The following tests demonstate the outstanding and unexpected superior performance results made possible by the present invention. Built detergent compositions which embody the novel builder compounds described herein provide a level of cleaning which is significantly superior to detergent compositions built with sodium tripolyphosphate and, in most all instances, superior to or comparable to cleaning levels obtained by tetradsodiu-m ethylenediaminetetraacetate. Sodium tripolyphosphate, STP, of course, is a condensed polyphosphate compound that is widely used in commercially available detergent compositions. It is a fairly well recognized standard builder 21- compound. Ethylenediaminetetraacetate, EDTA, is also a well known builder compound. Its value as a builder has been recognized previously, but it has not found general acceptance for such use because, among other reasons, it is too expensive to prepare.

Equally as important and surprising is the increased efiiciency of the detergent compositions which employ the propanetetraphosphonate compounds or the pentaphosphonate or hexaphosphonate of this invention as builders. The increased efliciency is manifested by the fact that even when the compositions of the present invention are used at concentrations far below currently recommended usage levels, equal performance results are obtained. This can be more fully appreciated by a close examination of Table I.

Three different performance characteristics of built detergent compositions were evaluated: cleaning, whiteness, and whiteness maintenance. For purposes of this invention, these terms have the following meanings. The term cleaning identifies the ability of a built detergent composition to remove soil from soiled fabrics. In part, this applies to the removal of deeply embedded soil deposits such as occurs, for instance, at the collars and cuffs of shirts and blouses. Whiteness is a more general term which identifies or represents a measurement of the ability of a built detergent composition to whiten areas which are only slightly or moderately soiled. Whiteness maintenance is a term which is used to identify the ability of a detergent formulation to prevent the soil which has been removed during a normal washing cycle from being redeposited upon the fabrics during the remainder of the laundering process, e.g., washing and rinsing, etc.

More specifically, the surprising building ability of the propanepolyphosphonate compounds of the present invention, using the tetraphosphonates as being representative, was discovered by washing naturally soiled white dress shirts with detergent compositions built with different builder materials. Shirts with detachable collars and cuffs were worn by male subjects under ordinary conditions for a certain period of time. The collars and cuffs were then detached and washed in an ordinary agitator type washing machine using solutions of the built detergent compositions being evaluated.

The washed and dried collars and cuffs were graded by means of a visual comparison with other collars and cuffs which had been similarly worn and soiled but which were washed with a standard built detergent composition. The visual comparisons were made by a trained panel of five people who were unfamiliar with any specific details and objectives of the tests. Their judgments were made independently.

Their visual judgments were expressed on a scale ranging from zero to ten. This determination records only the relative cleaning performance grades among the several compositions being evaluated. Zero on the cleaning grade scale represents a cleaning level obtained by washing with water alone, i.e., no detergent formulation. A value of ten represents the cleaning level of a specially formulated standardized detergent composition under optimum conditions. For purposes of this evaluation, a value grade of five represents a level of cleaning that is considered satisfactory in household practice. The test described above employed a detergent composition consisting only of an active detergent compound and a builder compound. For these tests, hexasodium dihydrogen propane-1,1,3,3-tetraphosphonate (abbreviated as PTEP in Table I) was used as a representative builder compound coming within the scope of the present invention. Results obtained with this representative material are presented along with results obtained with STP and EDTA in Table I.

Each of the several builder compounds was tested with detergent compounds which are representative of the previously disclosed detergent classes.

In order to obtain as accurate a measurement as possible of the builder property of each of the sample compounds,

none of the usual additives, such as sulfates, silicates, fluorescers, anti-redeposition agents, etc., were used in these tests. By limiting the compositions to only two ingredients, i.e., an active detergent and a builder, there could be no interference or masking over of the function of the builders. The concentration of the active detergent in the washing solution was constant at .03% by weight. The concentrations of the builders in the washing solutions varied and included concentrations of .02%, 03%, .O4%, .045%, and .06%. These percentages correspond to concentrations of .02, .03, .04, .045, and .06 grams per 100 ml. of water. Each builder was not tested at each of these concentrations, and this is made apparent from Table I.

In addition, the washing solutions containing seven grains per gallon hardness (equivalent CaCO were adjusted with NaOH to a pH of 10 or 11 as indicated in the table. The temperatures of the washing solutions Were F. or 140 F., also as indicated. The duration of the washing cycle was 10 minutes.

In Table I, a difference in the cleaning grading scale of 1 unit represents a significant difference. By this is meant that an average housewife could readily and consistently see a significant cleaning difference between any two fabrics which have scores separated by a magnitude of at least 1 unit.

From Table I, it will be seen that STP at a concentration of .06 grams/ ml. water scored a grade of 5, which, as previously noted, is a generally acceptable grade for ordinary household usage. At concentrations less than .06, however, it should be noted that the cleaning performance falls off markedly until at concentration of STP of .03 grams/100 ml. of water, STP scored just 1.4 units. EDTA at a concentration of .06%, or .06 grams per 100 ml. water, scored 7.6, significantly better than STP. However, at a concentration of .045 grams/100 ml., EDTA scored only 5.1; and at a concentration of .03 grams per 100 ml., the grading score for EDTA dropped off all the way to .4 unit.

On the oher hand, the representative builder compound of the present invention not only scored above STP on the grading scale, but it also demonstrated remarkable efficiency in maintaining superior cleaning grades even with lower concentrations, e.g., .02 grams/100 ml., .03 grams/100 ml. Water and .04 grams/100 ml. water. Hexa sodium dihydrogen propane-1,1,3,3-tetraphosphonate surprisingly demonstrated this unexpected degree of efficiency which, as can be seen from Table I, resulted in cleaning grades of 4, 7, 6.4, 7.2, and 7.0. Its cleaning superiority over STP at the .06 gram usage level is of a totally unexpected magnitude. The fact that this superiority actually increases at lower usage levels is singularly significant. Thus, at .03% concentration of PTEP, the cleaning grade is more than two cleaning units higher than the cleaning grade obtained with STP at double the concentration, i.e., .06% concentration (compare evaluations No. 2 and No. 7). Moreover, a comparison between evaluations N0. 2, No. 5, and No. 8 shows that at equal concentrations (.03 g./100 ml.) of PTEP, STP, and EDTA, the PTEP provides about 5-fold improvement over STP and about an 18-fold improvement over EDTA. These cleaning grades testify to the outstanding efficiency of the PTEP builder compounds of the present invention over such well recognized builders as STP and EDTA. It is noteworthy also that even as low a concentration of .02 grams/100 ml. of PTEP provides a cleaning level not significantly different from STP and EDTA at a Concentration of .06 grams/100 ml. of water.

Equally valuable advantages for PTEP can be noted in the cleaning scores obtained with a more powerful active detergent, tallow alkyl sulfate, as seen from evaluations 11 through 16. At an equal builder concentration of .06 grams/100 ml. water, the three builders perform at about the same level. At the lower concentration of 23 .03 grams/ 100 ml., however, the PTEP far outperformed the STP and EDTA builder compounds. 7

Evaluations 20-24 in which a zwitterionic detergentwas used as well as evaluations 2831 wherein a nonionic de-' tergent was used likewise demonstrate the outstanding and efficient cleaning results made possible by the builder compounds of the present invention.

Evaluations 25, 26, and 27 demonstrate that at an equal builder concentration of .06 gram/ml, the PTEP is on a parity with STP and EDTA with another zwitterionic detergent, 3-(coconutalkyldirnethylarnmonio)-2- hydroxy-propane-l-sulfonate.

The practical value of the remarkable efficiency of the compounds of the present invention will be readily apparent in situations of insufficient product usage and to formulators of built detergent compositions and especially to those interested in built liquid detergent compositions where special formulating problems are encountered, e.g., solubility, cost, etc. i

The collar and cuff samples washed in accordance with the preceding discussion, using the representative detergent and builder compounds, and for which cleaning results are presented in Table I, were thereafter examined for whiteness performance results.

TABLE I.CLEANING EVALUATIONS tion of Cleaning Detergent Builder Builder Grade (grams/100 ml. water) 1 Tetrapropylene Benzene Sull'onate. PTEP 02 4. 7 03 7. 2 O4 6. 4 06 7. O3 1. 4 045 3. 4 06 5. 0 03 0. 4 045 5. l 06 7. 6 03 9. l 06 9. 4 03 5. 1 06 9. 3 03 5. 7 06 8. 9 03 6. 9 06 6. 3 1l) 3-(Hexadecyl dimethyl PTEP 03 7. 9

ammonio)-propane-lsulfonate. "do STP 03 6. 7 STP .06 7.1 EDTA .045 7.6 23 do EDTA .06 s. 0 24- 3-(Cocouutalkyl dirnethyl PTE P 06 7. 7

anunonio)-2-hydroxy-propane-l-sulionate. 25 .do STP 06 7. 8 26 d0 EDTA 06 8. 0 27 Dodtyl dimethyl phosphine PTEP 03 7. 7

0x1 0. 28 -do STP 03 4. 5 29 "do... 06 6. 3 30 d0 EDTA 045 6.0

1 Water temperature 140 F., pH 10. 2 Water temperature 80 F., pH 11.

The whiteness measurements were made on the backs of the cuffs with a commercially available photoelectric reflectometer, i.e., a Hunter Color and Color Difference meter manufactured by Henry A. Gardner Laboratory, Inc. This instrument is designed to distinguish color differcnces and operates on the tristimulus colorimeter principle. According to this principle, a 45-degree diffuse reflectance of an incident light beam on a test specimen is measured through a combination of green, blue and 33111- ber filters. The electrical circuitry of the instrument is so designed that lightness and chromaticity values for the test specimen are read directly. The departure from white (TiO being taken as a standard white) of the test specimen is calculated by introducing the lightness and chromaticity values so obtained into a complex formula supplied by the manufacturer. An evaluation of relative whiteness performance compared to a standard detergent composition is thus obtained for the test formulations and interpolated into a 1-10 scale. A more comprehensiv'e description of this device and its mode of operation appears in Color In Business, Science and Industry by Deane B. Judd, pp. 260-262; published by John Wiley & Sons, New York (1952).

The clear performance and efiiciency advantages of the propane-1,1,3,3-tetraphosphonate compounds discussed above in connection with cleaning were likewise apparent in these whiteness measurements. The propane-1,13,3- tetraphosphonate of the present invention offered excellent whiteness results, e.g., always on a parity with STP or significantly superior thereto.

In no instance did either STP or EDTA show a clear advantage over the propane l,1,3,3 tetraphosphonate builder described herein; whiteness measurements taken of samples washed in .03% builder concentrations showed a clear efiiciency advantage for this builder.

The evaluation of whiteness maintenance capability of the respective builders was performed by the following method. Unsoiled swatches of cotton terry cloth were washed with the wash solutions obtained from the cleaning testsJIn other words, the uusoiled swatches are added to the dirty wash water from the cleaning tests. The swatches are dried and then the whiteness thereof is measured by a Hunter Color and Color-Difference Meter following the same procedure described above. The soil adhering to the swatches is a relative measure of soil which has been adsorbed from the washing solutions containing the aforementioned representative builders. Factors are involved here other than the antiredeposition characteristics of the built detergent composition. It is, however, one way of demonstrating this property; and for showing relative performance, the test is valuable.

By virtue of these tests, it was ascertained that the propane-1,1,3,3-tetraphosphonate builder compounds of the present invention have very valuable whiteness maintenance properties. In all instances, the hexasodium dihydrogen propane-l,1,3,3-tetraphosphonate provided superior whiteness maintenance results over STP and EDTA, or at least on a parity therewith. It should be appreciated that those instances where the whiteness maintenance results were comparable are actually examples of the increased efficiency of the PT EP builder compounds. This is true because the amount of soil which is available to be redeposited in fabrics is proportionately greater in those cases where more soil was removed during the washing cycle. The cleaning results tabulated in Table I show the improved cleaning results over STP or EDTA and establish that there is that much more soil to keep from redepositing. The whiteness measurement results mentioned above, therefore, show that PTEP outperforms STP and EDTA as an improved whiteness'maintenance builder.

In many industrial, institutional and household processes and products, a small amount of a metal ion contamination present in water may adversely affect color, stability, appearance, quality and saleability of a product or the efliciency of a process. The role of a sequestrant or complexing agent in helping to overcome such adverse eifects of metal ions is fairly well recognized and appreciated.

It is another embodiment of the present invention to provide a highly improved process for treating aqueous solutions containing polyvalent metal ions by adding to the solution an effective amount of propane-1,1,3,3-tetraphosphonate. Ordinarily this amount ranges from .25 ppm. to 10,000 ppm. of the aqueous solution. This aspect of the present invention is based on the discovery of the outstanding sequestering properties of the novel polyphosphonate compounds described herein.

Although special emphasis has been placed herein upon the propanetetraphosphonates and especially propane-l, 1,3,3-tetraphosphonate, propane-1,2,3,3-tetraphosphonate and propane-1,2,2,3-tetraphosphonate, it should be noted that the pentaphosphonates and the hexaphosphonates offer equally good performance results when employed as builders in detergent compositions.

The foregoing description of the present invention has been presented describing certain operable and preferred embodiments. It is not intended that the invention should be so limited since variations and modifications thereof will be obvious to those skilled in the art, all of which are within the spirit and scope of this invention.

What is claimed is:

1. A compound selected from the group consisting of propane 1,1,2,3 tetraphosphonic acid, propane-1,2,2,3- tetraphosphonic acid, propane-1,1,3,3-tetraphosphonic acid, water soluble salts thereof and lower alkyl esters thereof.

2. A compound of claim 1 wherein the water soluble salt is selected from the group consisting of alkali metal salts, ammonium salts and substituted ammonium salts.

3. A compound of claim 1 wherein the lower alkyl esters are selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl and isohexyl esters.

4. Propane-1,1,2,3-tetraphosphonic acid and water soluble salts thereof.

5. Propane-1,2,2,3-tetraphosphonic acid and water soluble salts thereof.

6. Propane-1,1,3,3-tetraphosphonic acid and water soluble salts thereof.

7. A process for preparing an ester of propane-1,1,3,3- tetraphosphonic acid which comprises reacting an alkali metal carbanion of a tetraloweralkyl methylenediphosphonate with dihalomethane in the presence of an organic solvent having no active hydrogen atoms selected from the group consisting of toluene and benzene where- 26 in said carbanion and said dihalomethane are employed respectively in a molar ratio of from about 12055 to about 1:10 at a temperature in the range of from about 30 C. to about 125 C. for a time period of from about 10 hours to about 100 hours.

8. A process according to claim 7 wherein the reaction temperature is in the range of from C. to 110 C. and the time period is from 25 to hours.

9. A process according to claim 7 wherein said carbanion and dihalomethane are employed respectively in a molar ratio of from about 1:0.75 to 1:5.

References Cited UNITED STATES PATENTS 3,159,581 12/1964 Diehl 260-502.4 3,202,579 8/1965 Berth et al. 260502.4 3,214,454 10/1965 Blaser et al. 260429.9 2,297,578 1/ 1967 Crutchfield et a1. 260-5024 3,299,123 1/1967 Fitch et al. 260502.4

FOREIGN PATENTS 701,850 1/1965 Canada. 1,194,852 11/1963 Germany. 1,206,264 12/ 1965 Germany. 1,408,414 7/1965 France.

940,138 10/1963 Great Britain.

981,252 1/1965 Great Britain.

LEON ZITVER, Primary Examiner. J. E. EVANS, Assistant Examiner. 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF PROPANE - 1,1,2,3 - TETRAPHOSPHONIC ACID, PROPANE-1,2,2,3TETRAPHOSPHONIC ACID, PROPANE-1,1,3,3-TETRAPHOSPHONIC ACID, WATER SOLUBLE SALTS THEREOF AND LOWER ALKYL ESTERS THEREOF.
 7. A PROCESS FOR PREPARING AN ESTER OF PROPANE-1,1,3,3TETRAPHOSPHONIC ACID WHICH COMPRISES REACTING AN ALKALI METAL CARBANION OF A TETRALOWERALKYL METHYLENEDIPHOSPHONATE WITH DIHALOMETHANE IN THE PRESENCE OF AN ORGANIC SOLVENT HAVING NO ACTIVE HYDROGEN ATOMS SELECTED FROM THE GROUP CONSISTING OF TOLUENE AND BENZENE WHEREIN SAID CARBANION AND SAID DIHALOMETHANE ARE EMPLOYED RESPECTIVELY IN A MOLAR RATIO OF FROM ABOUT 1:0.55 TO ABOUT 1:10 AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 30*C. TO ABOUT 125*C. FOR A TIME PERIOD OF FROM ABOUT 10 HOURS TO ABOUT 100 HOURS. 